Device for facilitating the servicing of magnetic plate recorders



United States Patent 7 Claims. 6:. 346-137) The invention disclosed herein is concerned with a magnetic recorder operating with circular recording plates or disks. The object of the invention is to facilitate, in connection with such recorder, the exchange of magnetic plates and to make the plate securing means readily accessible.

The magnetic plate lies, in the normal or resting condition of such recorder, upon a guide plate. Upon switching on the drive motor, the magnetic plate will therefore slip or slide upon the guide plate and eventually upon the magnetic heads projecting over the guide plate surface, until the stable operating condition is established. There is also the danger that the magnetic plate, lying upon the guide plate and attaching itself thereto by adhesion, is upon appearance of the full torque overstressed and permanently deformed. A permanently deformed plate is made useless for further utilization thereof.

Upon operatively disconnecting the recorder, the drive motor comes owing to inertia relatively very slowly to a stop, and the plate slides during this interval upon theguide plate and the magnetic heads. Particles can thereby be detached from the magnetic layer, resulting in fault areas in such layer.

It is moreover diflicult to grip the thinand pliable magnetic plate when it lies upon a plane surface. It is accordingly desirable that the plate be lifted for an exchange thereof.

The invention is concerned with a device for facilitating the starting, servicing and operation of magnetic recorders operating with circular magnetic plates, comprising means for freely suspending the plate with respect to the guide plate.

In accordance with the invention, there is provided a blower which is set in operation for the lifting of the plate from the guide plate during the start and stop operations of the motor and during the exchanging of plates. In

" accordance with a further feature of the invention, the

recorder is provided with a blower motor and a separate plate drive motor, and with a relay circuit for independently controlling the operation of said motors.

These devices are operative to produce an air cushion between the magnetic plate and the guide plate, dust particles which accumulate upon the guide plate during periods of rest of the recorder being propelled outwardly; it is moreover easier to grip and to exchange the plate in its suspended condition.

Details of the invention will appear from the claims and from the description which is rendered below with reference to the accompanying drawings.

FIG. 1 shows the arrangement of parts with a plate drive motor and a blower motor; and

FIG. 2 represents a circuit for controlling the plate drive motor and the blower motor.

Referring now to FIG. 1, numeral 1 indicates a base plate to which are fastened the plate drive motor 2 and the blower motor 3. The latter drives, over a belt 4, the hollow shaft 5 of the blower 6. The hollow shaft 5 is mounted upon the shaft 7 of the plate drive motor 2. Upon the shaft 7 is fixedly secured the plate mounting or holder 8. A second base plate It is connected with the base plate 1 by means of side wall members 1tia, thus delimiting a chamber in which the belt 4 operates.

Upon the second base. plate 10 is fastened a drumshaped cap11 which carries the guide plate 12, such cap and also the guide plate being provided with a circular hole respectively formed therein. Through the corresponding holes projects the plate mounting or holder 8, leaving annular gaps 13. The plate holder 8 carries an air'choke or deflection disk 14 which is rotatable therewith. Known and suitable means may be provided (not shown) for axially shifting the disk 14. This disk forms with the wall of the cap 11 a gap 13a through which air can flow along and then through the annular gap 13. The magnetic plate 15 may be fastened to the holder 8 by utilizing known and suitable means (not shown).

The guide plate 12 carries in customary manner magnetic heads 16 and erase heads 17. The guide plate 12 and the magnetic plate 15 normally lying thereon, are covered by a cover 18 which is provided with ribs 19. The cover 18 is pivotally secured at a hinge 2h. The cover 18 operates upon opening and closing thereof, a switch at, which is thus correspondingly actuated. The function of the ribs 19 is to prevent strong circulation of the air between the plate and the cover, which circulation would result in suction, with the effect that the magnetic plate 15 would be marginally lifted with respect to the magnetic heads.

Actuation of the switch [2 to the On position (FIG. 2) will operatively connect the blower motor 3 (FIG. 1), such motor driving, through the medium of the belt 4, the hollow shaft 5 and therewith the blower 6. An air current 21 will thus be produced, such current flowing through the gaps 13a and 13, and continuing to flow along the gap 131: between the magnetic plate 15 and the guide plate 12, thereby lifting the magnetic plate from the guide plate 12. The plate drive motor 2 is now switched on and the blower 6 is shortly thereafter discushion between the magnetic plate 15 and the guide.

plate 12, sliding of the plate 15 on the guide plate is prevented. The air in the gap 1312 between the magnetic plate 15 and the guide plate 12 is, by the rotation of the magnetic plate driven outwardly, the air current 21 however continuing to flow after disconnection of the blower motor, and the magnetic plate 15 remaining lifted with respect to the guide plate 12. Variation of the width of the gap 13a permits regulation of the air current flowing through the gap 13 and therewith regulation of the spacing of the magnetic plate 15 with respect to the guide plate 12 and the magnetic heads, 16, 17 connected therewith.

Actuation of the switch b to the OE position (FIG. 2) results in brief operative connection of the blower motor 3 and disconnection of the plate drive motor 2, which is accomplished by the relay circuit to be presently described. The air current 21 is, as above described, maintained, thus maintaining the air cushion between the magnetic plate 15 and the guide plate 12. The blower motor 3 is disconnected after about 40 seconds, that is, after the braking of the plate drive motor 2.

As previously noted, the switch d is actuated upon opening the cover 18. The blower motor 3 is thereby operatively connected and the plate drive motor 2 is disconnected. This is accomplished by the relay circuit to be presently described. The magnetic plate 15 floats now above the guide plate 12, without rotating, and can be readily gripped and exchanged.

Referring now to the relay circuit shown in FIG. 2, characters A, H and M designate relays, a1, a2, h, m1 and m2 being contacts controlled by the respective relays; Z is a timing relay controlling the contact 2; the control switch is designated by b, the cover controlled switch by a, and the switch controlled by a centrifugal device connected to the blower motor is designated by f.

' Upon actuating the control switch b to the On position, current will be supplied to the relay A in a circuit extending from A, d, b, relay A energizing and actuating its contact a2 to connect the blower 3 in an operating circuit. Upon assuming a given speed of rotation, the blower motor 3 causes operative actuation of the centrifugally-controlled switch thereby closing circuits for the energization of relays H and M, over circuits respectively extending from all, M to and f z, H to The relay M closes at its contact mZ'a circuit for the operation of the plate drive motor 2 and the relay H, by actuating its contact h disconnects the circuit for the blower motor 3. Relay M remains energized in a holding circuit over its contact ml even after the centrifugally controlled switch is restored to its normal position; relay H also remaining energized.

Opening of the cover 18 results in opening of the switch d and consequently in opening of the circuit for relay A which restores to normal, thereby restoring its contact a2 and thus operatively connecting the blower motor 3. Upon assuming a given speed of rotation, the blower motor 3 causes actuation ofthe switch 1 which opens the circuit for the relay M (contact all being open), relay M restoring to normal and opening its contact m2, thereby disconnecting the plate drive motor 2. This conditionoperatively connected blower motor and disconnected plate drive motor-continues until the cover 18 is closed again, thereby also closing the switch d. The relay A is now again energized, actuates its contact all to close the energizing circuit for the relay M which remains energized in the holding circuit over its contact m1, contact a2 of the relay A opening and disconnecting the blower motor 3. The switch restores to its normal position. The relay M actuates its contact m2, thereby operatively connecting the plate drive motor. The operating condition now corresponds again to the condition in which it had been prior to the opening of the cover 18.

Actuation of the control switch 12 to the Ofr position opens the circuit for relay A which deenergizes and connects the blower motor 3 by the actuation of its contact :12. Upon assuming a given speed of rotation, the motor 3 causes operative actuation of the switch 1'', such switch opening the circuit of relay M which restores to normal, opening its contact m2 and thereby disconnecting the plate drive motor. The relay Z, which is is a time controlled relay and actuates its contact z, for example, after 40 seconds, is placed in an energizing circuit which extends from 1, m1, Z, b, At the lapse of 40 seconds, the contact z interrupts the circuit of relay H,

4 such relay deenergizing and disconnecting the blower motor 3 at its contact h. l

The servicing of the arrangement is further facilitated and a spatially favorable disposition is obtained, by placing the apparatus shown in FIG. 1 at an angle, inclined to the front, mounted upon a suitable stand or the like.

Changes may be made within the scope and spirit of the appended claims which define what is believed to be new and desired to have protectedby Letters Patent.

I claim:

1. A device for facilitating the operation and servicing of a recorder operating with circular magnetic plates, particularly the manipulation of suchplates, comprising a guide plate above which a magnetic plate is placed for the operation thereof, a motor for driving said magnetic plate, a blower for producing an air current for lifting the magnetic plate with respect to the guide plate, a motor for actuating said blower, and means for operatively actuating said blower motor so .as to produce. an air current to lift said magnetic plate with respect to said guide plate out of normal operative position during periods of starting and stopping the operation of said plate drive motor and during periods of manipulating the mag netic plate.

2. A device according to claim 1, comprising a relay circuit means for independently controlling the operation of said motors.

3. A device according to claim 2, comprising a switch which is controlled by the opening and closing operations of a cover forming part of the recorder, said switch forming part of said circuit. A

4. A device according to claim 3, comprising a switch controlled by said blower motor, said switch forming part of said circuit.

' 5. A device according to claim 3, comprising a time controlled member forming part of said circuit.

I 6. A device according to claim 3, wherein said cover is provided with ribs for impeding air circulation in the space above said magnetic plate.

7. A device according to claim 1, incorporated in a recorder having a cover and being placed so that the. cover and the parts of said device are on an inclineto facilitate access to said parts.

liteterences Cited by the Examiner UNITED STATES PATENTS 8/60 Formenko 179-1002 4/62 Lynott 179-40032 

1. A DEVICE FOR FACILITATING THE OPERATION AND SERVICING OF A RECORDER OPERATING WITH CIRCULAR MAGNETIC PLATES, PARTICULARLY THE MANIPULATION OF SUCH PLATES, COMPRISING A GUIDE PLATE ABOVE WHICH A MAGNETIC PLATE IS PLACED FOR THE OPERATION THEREOF, A MOTOR FOR DRIVING SAID MAGNETIC PLATE, A BLOWER FOR PRODUCING AN AIR CURRENT FOR LIFTING THE MAGNETIC PLATE WITH RESPECT TO THE GUIDE PLATE, A MOTOR FOR ACTUATING SAID BLOWER, AND MEANS FOR OPERATIVELY ACTUATING SAID BLOWER MOTOR SO AS TO PRODUCE AN 